The present invention relates to a waterproof type of electric connector, more particularly to such an electric connector for use in connecting electric machines and apparatus to an electric power supply born in transportation means in such a water-tight fashion that no electric shortcircuit between conductors be caused by water invasion due to the capillary action in thhe very small gap between the core and the insulation sheath of an insulated wire. Such a water invasion due to the capillary action in the very small gap between the core and the insulation sheath of a selected insulated wire is likely to take place in case where the end of the insulated wire opposite to that of the insulated wire which is connected to the electric connector, is exposed to the surrounding atomosphere.